Abstract: A system is described that can detect pressure anomalies within a data center, generate an alert when anomalies are detected, and initiate remediative actions. The system monitors each of a plurality of fans used to dissipate heat generated by one or more servers to obtain data that indicates how an actual speed of each of the fans relates to a target speed thereof. The system compares the obtained data to reference data that indicates, for each of the plurality of fans, how an actual speed of the fan relates to a target speed thereof in a substantially pressure-neutral environment. Based on the comparison, the system determines whether or not a pressure anomaly exists. If the system determines that a pressure anomaly exists, then the system may perform various actions such as generating an alert and modifying a manner of operation of one or more of the fans or servers.

Abstract: A method for detecting an improper storage system configuration is provided. The method includes receiving, within a first switch, an indication of a configuration change of a storage system. The method also includes performing device discovery to identify devices operatively coupled to the first switch. The method also includes receiving a storage device identifier of a storage device operatively coupled to the first switch. The method also includes searching a repository for the storage device identifier to determine whether the storage device is managed by a second switch.

Abstract: Techniques for retrieving data blocks are provided. In one aspect, a storage fabric address of a controller associated with a data block is retrieved by a node. If the node is on the same storage fabric as the retrieved address, the data block may be retrieved over the storage fabric. In another aspect, a directory server maintains mappings of data blocks to storage fabric addresses of controllers associated with the data blocks. A request for the location of the data block includes the storage fabric address of the associated controller.

Abstract: A hardware device detects change messages broadcast within a system. The system includes the hardware device, one or more controller devices, one or more expander devices, and one or more target devices interconnected among one another. The hardware device determines whether the change messages were broadcast within the system every first period of time or less for at least a second period of time, the first period of time less than the second period of time. In response to determining that the change messages were broadcast within the system every first period of time or less for at least the second period of time, the hardware devices signals that an error has been detected.

Abstract: In a method to zone data to a virtual machine, support information is exchanged between a physical controller and an expander, the support information comprising an indication of an ability of the physical controller and the expander to support thereon a set of virtual controllers and a set of virtual physical layers (virtual PHYs), respectively. In response to a positive indication sending a list of SAS addresses to the expander, a list of SAS addresses is sent to the expander. Then, a first SAS address of the list of SAS addresses is assigned to a first virtual PHY of the set of virtual PHYs, wherein the assigning is performed by the expander, and wherein the first virtual PHY at an assigned SAS address corresponds to a first virtual controller of the set of virtual controllers.

Abstract: A serial attached small computer system interface (SAS) expander for providing a virtual tape drive. The expander includes a virtual tape manager to generate a virtual tape virtual PHY capable of being part of a zone group wherein the virtual tape virtual PHY comprises drive bays which support disk drives for emulation of tape drives.

Abstract: In a method to zone data to a virtual machine, support information is exchanged between a physical controller and an expander, the support information comprising an indication of an ability of the physical controller and the expander to support thereon a set of virtual controllers and a set of virtual physical layers (virtual PHYs), respectively. In response to a positive indication sending a list of SAS addresses to the expander, a list of SAS addresses is sent to the expander. Then, a first SAS address of the list of SAS addresses is assigned to a first virtual PHY of the set of virtual PHYs, wherein the assigning is performed by the expander, and wherein the first virtual PHY at an assigned SAS address corresponds to a first virtual controller of the set of virtual controllers.

Abstract: A system is described that can detect pressure anomalies within a data center, generate an alert when anomalies are detected, and initiate remediative actions. The system monitors each of a plurality of fans used to dissipate heat generated by one or more servers to obtain data that indicates how an actual speed of each of the fans relates to a target speed thereof. The system compares the obtained data to reference data that indicates, for each of the plurality of fans, how an actual speed of the fan relates to a target speed thereof in a substantially pressure-neutral environment. Based on the comparison, the system determines whether or not a pressure anomaly exists. If the system determines that a pressure anomaly exists, then the system may perform various actions such as generating an alert and modifying a manner of operation of one or more of the fans or servers.

Abstract: Techniques for retrieving data blocks are provided. In one aspect, a storage fabric address of a controller associated with a data block is retrieved by a node. If the node is on the same storage fabric as the retrieved address, the data block may be retrieved over the storage fabric. In another aspect, a directory server maintains mappings of data blocks to storage fabric addresses of controllers associated with the data blocks. A request for the location of the data block includes the storage fabric address of the associated controller.

Abstract: A method for detecting an improper storage system configuration is provided. The method includes receiving, within a first switch, an indication of a configuration change of a storage system. The method also includes performing device discovery to identify devices operatively coupled to the first switch. The method also includes receiving a storage device identifier of a storage device operatively coupled to the first switch. The method also includes searching a repository for the storage device identifier to determine whether the storage device is managed by a second switch.

Abstract: Techniques for operating a serial attached SCSI (SAS) expander that includes a latency table comprising entries of outbound PHYS with latency values associated with connections between inbound PHYs and outbound PHYs. A storage management module to, in response to receipt of a command from an initiator device associated with an inbound PHY to route data to a target device associated with an outbound PHY, select from the latency table a random outbound PHY from among a plurality of outbound PHYs, wherein the random selection is based on weighted average of latency values of the outbound PHY entries of the latency table.

Abstract: Techniques for retrieving data blocks are provided. In one aspect, a storage fabric address of a controller associated with a data block is retrieved by a node. If the node is on the same storage fabric as the retrieved address, the data block may be retrieved over the storage fabric. In another aspect, a directory server maintains mappings of data blocks to storage fabric addresses of controllers associated with the data blocks. A request for the location of the data block includes the storage fabric address of the associated controller.

Abstract: Examples disclosed herein relate to determination of whether storage domain paths for storage devices include a common routing module. Examples include determining whether the storage domain paths include a common routing module if a threshold stage of a storage device recovery procedure has been reached for a threshold number of storage devices within a detection time period.

Abstract: An example expander includes a processor, a switch, and a plurality of physical layer devices (PHYs). The processor is to detect an error condition and, in response to detecting the error condition, cause the expander to enter a reduced functionality mode which keeps the switch and the plurality of physical layer devices (PHYs) operating notwithstanding the error condition.

Abstract: A method includes detecting a topology change on a link in a network and determining which zone group corresponds to the topology change. The method also includes identifying a zone group in the network that is permitted to access a device on said link and determining an address of an expander that has the zone group permitted to access the device on the link. The method further includes generating an expander-targeted zoned broadcast command to report a topology change in the network. The expander-targeted zoned broadcast command has, as a destination address, the address of the expander determined to have a zone group permitted to access a device on the link.

Abstract: In one example in accordance with aspects of the present disclosure, an expander is provided. The expander comprises a workload scheduling module to cause the expander to enter a first mode of operation where the expander processes interrupts, and further to enter a second mode of operation where the expander processes interrupts for up to a predetermined time period before responding to at least one of Serial Management Protocol (SMP) commands and Serial SCSI Protocol (SSP) commands with a retry message.

Abstract: In one example, a method for assigning zone groups to a physical storage enclosure includes comparing a first signature assigned to a number of first storage devices in an online physical storage enclosure against a second signature assigned to a number of second storage devices in a first offline physical storage enclosure of a number of offline physical storage enclosures. The method may further include, in response to a determination that the first signature matches the second signature, copying zone groups from the first offline physical storage enclosure associated with the second signature to the online physical storage enclosure.

Abstract: A method for detecting an improper storage system configuration is provided. The method includes receiving, within a first switch, an indication of a configuration change of a storage system. The method also includes performing device discovery to identify devices operatively coupled to the first switch. The method also includes receiving a storage device identifier of a storage device operatively coupled to the first switch. The method also includes searching a repository for the storage device identifier to determine whether the storage device is managed by a second switch.

Abstract: A hardware device detects change messages broadcast within a system. The system includes the hardware device, one or more controller devices, one or more expander devices, and one or more target devices interconnected among one another. The hardware device determines whether the change messages were broadcast within the system every first period of time or less for at least a second period of time, the first period of time less than the second period of time. In response to determining that the change messages were broadcast within the system every first period of time or less for at least the second period of time, the hardware devices signals that an error has been detected.

Abstract: An example method includes (i) creating, by a first serial attached SCSI (SAS) switch, a first topology map describing a portion of a SAS fabric associated with the first SAS switch; (ii) receiving, at the first SAS switch and from a second SAS switch, a second topology map describing a portion of the SAS fabric associated with the second SAS switch; and (iii) merging, by the first SAS switch, the first topology map and the second topology map to produce a consolidated topology map of the SAS fabric.